Survivals following discontinuation of PD-1 inhibitor treatment in advanced melanoma patients.

The aim of this study was to evaluate overall survival post-treatment discontinuation survival (OS PTD ) in advanced melanoma patients started on immunotherapy. This retrospective study included all unresectable advanced or metastatic melanoma patients who had permanent treatment discontinuation after receiving at least one cycle of palliative-intent programmed death-1 ± cytotoxic T-lymphocyte associated protein-4 inhibitor treatment from 2014 to 2019. Indications of permanent treatment discontinuation included treatment completion, toxicity or progression. OS PTD was defined as a time of permanent treatment discontinuation to the time of death. Our study ( N = 96) had 27, 12 and 57 patients who discontinued PD-1 inhibitor treatment due to treatment completion, toxicity and progression, respectively. Median treatment durations received for the treatment completion, toxicity and progression groups were 24, 6 and 3 months, respectively. As expected those patients who had disease progression on immunotherapy had very poor survival compared to those that completed treatment or stopped due to toxicity. A multivariable Cox model excluding the patients who progressed indicated no significant OS PTD differences between the toxicity and treatment completion group (HR, 0.894; 95% CI, 0.232-3.449; P = 0.871) who received single or dual immunotherapy. Our real-world study highlighted similar, durable survival at PD-1 inhibitor discontinuation due to either toxicity or treatment completion, despite longer treatment duration received in the completion group than toxicity group. Patients with progression on PD-1 inhibitor treatment have very poor survival. Our findings must be interpreted with caution due to its retrospective nature and small sample size.

Improved overall survival in dual compared to single immune checkpoint inhibitors in BRAF V600-negative advanced melanoma.

Aim: To evaluate the efficacy of dual versus single immune checkpoint inhibitors (ICI) in BRAF wild-type advanced melanoma patients. Materials & methods: A retrospective study of all advanced BRAF wild-type melanoma patients on palliative-intent ICI between 2015 and 2020 (n = 67). Results: Dual ICI had better overall survival (OS) when compared with single ICI in BRAF wild-type patients (hazard ratio: 0.204; 95% CI: 0.064-0.649; p = 0.007), but lost its statistical significance (median OSl not reached vs 20.9 months; p = 0.213; adjusted hazard ratio: 0.475; 95% CI: 0.164-1.380; p = 0.171) when only including patients treated after 2018 when dual ICI was funded in our province. Dual ICI were significantly associated with more frequent (p = 0.005) and severe (p = 0.026) immune-related adverse events, and required more immune-related adverse events-indicated systemic corticosteroid use (p < 0.001) compared with single ICI. Conclusion: While limited by small sample size and retrospective nature, dual ICI may have non statistically significant trend toward better OS efficacy when compared with single ICI in BRAF V600 wild-type advanced melanoma patients.

Treatment Patterns and Outcomes of Women with Symptomatic and Asymptomatic Breast Cancer Brain Metastases: A Single-Center Retrospective Study.

BACKGROUND: Breast cancer is the most common cancer among women worldwide and the second leading cause of brain metastases (BrM). We assessed the treatment patterns and outcomes of women treated for breast cancer BrM at our institution in the modern era of stereotactic radiosurgery (SRS). MATERIALS AND METHODS: We conducted a retrospective analysis of women (≥18 years of age) with metastatic breast cancer who were treated with surgery, whole brain radiotherapy (WBRT), or SRS to the brain at the Sunnybrook Odette Cancer Centre, Toronto, Canada, between 2008 and 2018. Patients with a history of other malignancies and those with an uncertain date of diagnosis of BrM were excluded. Descriptive statistics were generated and survival analyses were performed with subgroup analyses by breast cancer subtype. RESULTS: Among 683 eligible patients, 153 (22.4%) had triple-negative breast cancer, 188 (27.5%) had HER2+, 246 (36.0%) had hormone receptor (HR)+/HER2-, and 61 (13.3%) had breast cancer of an unknown subtype. The majority of patients received first-line WBRT (n = 459, 67.2%) or SRS (n = 126, 18.4%). The median brain-specific progression-free survival and median overall survival (OS) were 4.1 months (interquartile range [IQR] 1.0-9.6 months) and 5.1 months (IQR 2.0-11.7 months) in the overall patent population, respectively. Age >60 years, presence of neurological symptoms at BrM diagnosis, first-line WBRT, and HER2- subtype were independently prognostic for shorter OS. CONCLUSION: Despite the use of SRS, outcomes among patients with breast cancer BrM remain poor. Strategies for early detection of BrM and central nervous system-active systemic therapies warrant further investigation. IMPLICATIONS FOR PRACTICE: Although triple-negative breast cancer and HER2+ breast cancer have a predilection for metastasis to the central nervous system (CNS), patients with hormone receptor-positive/HER2- breast cancer represent a high proportion of patients with breast cancer brain metastases (BrM). Hence, clinical trials should include patients with BrM and evaluate CNS-specific activity of novel systemic therapies when feasible, irrespective of breast cancer subtype. In addition, given that symptomatic BrM are associated with shorter survival, this study suggests that screening programs for the early detection and treatment of breast cancer BrM warrant further investigation in an era of minimally toxic stereotactic radiosurgery.

The incidence of brain metastases among patients with metastatic breast cancer: a systematic review and meta-analysis.

BACKGROUND: Patients with metastatic breast cancer (MBC) are living longer, but the development of brain metastases often limits their survival. We conducted a systematic review and meta-analysis to determine the incidence of brain metastases in this patient population. METHODS: Articles published from January 2000 to January 2020 were compiled from four databases using search terms related to breast cancer, brain metastasis, and incidence. The overall and per patient-year incidence of brain metastases were extracted from studies including patients with human epidermal growth factor receptor-2 positive (HER2+), triple negative, and hormone receptor (HR)+/hormone receptor negative (HER2-) MBC; pooled overall estimates for incidence were calculated using random effects models. RESULTS: 937 articles were compiled, and 25 were included in the meta-analysis. Incidence of brain metastases in patients with HER2+ MBC, triple negative MBC, and HR+/HER2- MBC was reported in 17, 6, and 4 studies, respectively. The pooled cumulative incidence of brain metastases was 31% for the HER2+ subgroup (median follow-up: 30.7 months, IQR: 24.0-34.0), 32% for the triple negative subgroup (median follow-up: 32.8 months, IQR: 18.5-40.6), and 15% among patients with HR+/HER2- MBC (median follow-up: 33.0 months, IQR: 31.9-36.2). The corresponding incidences per patient-year were 0.13 (95% CI: 0.10-0.16) for the HER2+ subgroup, 0.13 (95%CI: 0.09-0.20) for the triple negative subgroup, and only 0.05 (95%CI: 0.03-0.08) for patients with HR+/HER2- MBC. CONCLUSION: There is a high incidence of brain metastases among patients with HER2+ and triple negative MBC. The utility of a brain metastases screening program warrants investigation in these populations.

PD-L1 expression and clinical outcomes in patients with advanced urothelial carcinoma treated with checkpoint inhibitors: A meta-analysis.

CONTEXT: Five checkpoint inhibitors have been approved as 1st line (cisplatin-ineligible) or 2nd line therapies for patients with metastatic urothelial carcinoma of the bladder. As only about 30% of patients respond, the need for a biomarker for patient selection exists. OBJECTIVE: To determine if PD-L1 expression is a prognostic factor of objective response rate (ORR) and overall survival (OS) in patients with urothelial carcinoma being treated with checkpoint inhibitors. EVIDENCE ACQUISITION: A search of PubMed and major conference proceedings identified trials of PD-L1 inhibitors as first- or second-line therapies for metastatic bladder cancer. Odds ratios (OR) for ORR and OS compared PD-L1 positive and PD-L1 negative patients. Data were weighted and pooled in a meta-analysis, and subgroup analyses compared PD-L1 status cut-offs. EVIDENCE SYNTHESIS: Ten studies comprising 2755 patients were identified, of which 2030 patients (74%) received immune checkpoint inhibitors. Eight studies were eligible for ORR analysis (1530 patients) and five studies for OS (829 patients). PD-L1 patients had a significantly higher ORR than PD-L1 negative patients (1.82, 95%CI 1.18-2.77; p = 0.007). Weighted mean OS was 11.5 months (range 8.7-15.9 months). PD-L1 status was not prognostic for 12 month OS (OR = 0.81, 95%CI 0.47-1.40; p = 0.45). CONCLUSION: In patients treated with PD-L1 inhibitors for metastatic urothelial carcinoma, PD-L1 status is prognostic for ORR but not OS. Our findings warrant additional investigation. PATIENT SUMMARY: Five immunotherapy drugs are approved for bladder cancer therapy. PD-L1 expression predicts higher ORR but not OS. More data is needed to identify the patient population most benefitted by immunotherapy.

Actions of a hydrogen sulfide donor (NaHS) on transient sodium, persistent sodium, and voltage-gated calcium currents in neurons of the subfornical organ.

Hydrogen sulfide (H2S) is an endogenously found gasotransmitter that has been implicated in a variety of beneficial physiological functions. This study was performed to investigate the cellular mechanisms underlying actions of H2S previously observed in subfornical organ (SFO), where H2S acts to regulate blood pressure through a depolarization of the membrane and an overall increase in the excitability of SFO neurons. We used whole cell patch-clamp electrophysiology in the voltage-clamp configuration to analyze the effect of 1 mM NaHS, an H2S donor, on voltage-gated potassium, sodium, and calcium currents. We observed no effect of NaHS on potassium currents; however, both voltage-gated sodium currents (persistent and transient) and the N-type calcium current had a depolarized activation curve and an enhanced peak-induced current in response to a series of voltage-step and ramp protocols run in the control and NaHS conditions. These effects were not responsible for the previously observed depolarization of the membrane potential, as depolarizing effects of H2S were still observed following block of these conductances with tetrodotoxin (5 µM) and ω-conotoxin-GVIA (100 nM). Our studies are the first to investigate the effect of H2S on a variety of voltage-gated conductances in a single brain area, and although they do not explain mechanisms underlying the depolarizing actions of H2S on SFO neurons, they provide evidence of potential mechanisms through which this gasotransmitter influences the excitability of neurons in this important brain area as a consequence of the modulation of multiple ion channels.

Hydrogen sulfide regulates cardiovascular function by influencing the excitability of subfornical organ neurons.

Hydrogen sulfide (H2S), a gasotransmitter endogenously found in the central nervous system, has recently been suggested to act as a signalling molecule in the brain having beneficial effects on cardiovascular function. This study was thus undertaken to investigate the effect of NaHS (an H2S donor) in the subfornical organ (SFO), a central nervous system site important to blood pressure regulation. We used male Sprague-Dawley rats for both in vivo and in vitro experiments. We first used RT-PCR to confirm our previous microarray analyses showing that mRNAs for the enzymes required to produce H2S are expressed in the SFO. We then used microinjection techniques to investigate the physiological effects of NaHS in SFO, and found that NaHS microinjection (5 nmol) significantly increased blood pressure (mean AUC = 853.5±105.7 mmHg*s, n = 5). Further, we used patch-clamp electrophysiology and found that 97.8% (88 of 90) of neurons depolarized in response to NaHS. This response was found to be concentration dependent with an EC50 of 35.6 µM. Coupled with the depolarized membrane potential, we observed an overall increase in neuronal excitability using an analysis of rheobase and action potential firing patterns. This study has provided the first evidence of NaHS and thus H2S actions and their cellular correlates in SFO, implicating this brain area as a site where H2S may act to control blood pressure.

Apelin acts in the subfornical organ to influence neuronal excitability and cardiovascular function.

Apelin is an adipocyte-derived hormone involved in the regulation of water balance, food intake and the cardiovascular system partially through actions in the CNS. The subfornical organ (SFO) is a circumventricular organ with identified roles in body fluid homeostasis, cardiovascular control and energy balance. The SFO lacks a normal blood-brain barrier, and is thus able to detect circulating signalling molecules such as angiotensin II and leptin. In this study, we investigated actions of apelin-13, the predominant apelin isoform in brain and circulatory system, on the excitability of dissociated SFO neurons using electrophysiological approaches, and determined the cardiovascular consequences of direct administration into the SFO of anaesthetized rats. Whole cell current clamp recording revealed that bath-applied 100 nm apelin-13 directly influences the excitability of the majority of SFO neurons by eliciting either depolarizing (31.8%, mean 7.0 ± 0.8 mV) or hyperpolarizing (28.6%, mean -10.4 ± 1.8 mV) responses. Using voltage-clamp techniques, we also identified modulatory actions of apelin-13 on specific ion channels, demonstrating that apelin-13 activates a non-selective cationic conductance to depolarize SFO neurons while activation of the delayed rectifier potassium conductance underlies hyperpolarizing effects. In anaesthetized rats, microinjection of apelin into SFO decreased both blood pressure (BP) (mean area under the curve -1492.3 ± 357.1 mmHg.s, n = 5) and heart rate (HR) (-32.4 ± 10.39 beats, n = 5). Our data suggest that circulating apelin can directly affect BP and HR as a consequence of the ability of this peptide to modulate the excitability of SFO neurons.